1. Field of the Invention
This invention relates to chain lubricating systems and particularly to an oil reservoir adapted to lubricate a horizontal drive chain used on wheel line irrigation systems.
2. State of the Art
Wheel line irrigation systems are commonly used throughout the United States for irrigating agricultural lands. Generally, the wheel line irrigation systems include a four wheeled motorized drive carriage of the type shown in FIG. 1 of the drawing. Extending laterally in each direction from the drive carriage are a series of connected four to five inch diameter aluminum water carring pipes. The connected pipes can extend out laterally to a length of about 152 meters (500 feet), in both directions. At intervals of about 15 meters (50 feet), a 1.5 to 3.0 meters (5 to 10 feet) diameter roll wheel is fixed to the pipe for carrying the pipe across a field on movement of the drive carriage.
One end of the laterally extending pipe is adapted with a coupler for connecting to a water main. The other end of the pipe is normally closed. Sprinkling heads are mounted in spaced alignment along the pipes intermediate the follow wheels for distributing water carried by the pipe onto an agricultural field. The irrigation system is moved longitudinally down the field by a geared six to seven horsepower gasoline engine.
Power from the gasoline engine is transferred to the drive carriage through an over sized bull gear to which are mounted a pair of side by side drive sprockets. The front and rear axle of the drive carriage contains a geared sprocket fixed thereto. A continuous chain connects one of the drive sprockets with the sprocket fixed to the front axle. A second continuous chain connects the other drive sprocket with the sprocket fixed to the rear axle.
As stated above, power from the gasoline engine is transferred to a bull gear. The bull gear contains an annular opening through which the water carrying pipe passes and is secured thereto. This arrangement causes the pipe to slowly rotate as the bull gear rotates. The torque generated by the slowly turning water pipe causes the follow wheels fixed thereto to turn and thereby "roll" the laterally extending water pipe down the field.
As indicated above, the drive carriage is moved first in one direction and then in the other direction by means of a pair of drive chains. The first drive chain is connected to the front axle of the drive carriage and the geared gasoline engine. The second drive chain connects the rear axle of the drive carriage and the geared gasoline engine. It is for these drive chains that the lubricating reservoir of this invention was designed and which will subsequently be discussed in greater detail.
The open drive chains measure about 12 to 18 feet in length and are relatively expensive to replace on a periodic basis.
One of the major problems associated with the wheel line irrigation systems above described is that the drive chains are normally exposed, that is, they are not contained within a housing. As a result, the interconnected rollers and links which make up the chain are continually subjected to moisture from the sprinkling system, as well as, dirt and dust from the fields. If the chains are not lubricated on a regular basis, the links and rollers become "stiff" and eventually lock creating an irregular or jerking motion to the water carrying pipe during rotation. This jerking action causes a substantially increased torque force on the laterally extending water carrying pipe. As the torque force is increased the laterally extending pipes are weakened causing crimping and even snapping of the pipes. This results in costly repairs and down-time which has an adverse effect on costs of operation and crop production.
In addition, to the above, the chain is continually exposed to sun, dust, and sand which tends to remove or dry the lubricants that have been applied manually to the chain. This subjects the chain and sprocket system to servere abrasive wear necessitating frequent repair and replacement. Such repairs also result in unnecessary costly down-time which, in turn, adversely affects crop production.
Since the irrigation systems are also used for applying fertilizers, insecticides, and herbicides to the fields, the opportunities for the chain to be exposed to corrosive elements are substantially increased.